This invention relates to an electrochemical marking process and, in particular, to a programable marking head suitable for use in an electrochemical marking process.
In the electrochemical marking process, information is recorded upon a grounded conductive part by firing an electrode against the part in the presence of an electrolyte. Conventionally the charge pattern passing between the head and the receiving surface is shaped by a stencil having the desired design cut therein. An etch of the design is imaged upon the receiving surface which is filled with an oxide of the base metal to form a clearly discernible mark. The mark will not harm or deform the part and, as a result, the electrochemical process can be used to mark precision-made parts which could not otherwise be marked using other metal deforming techniques.
Although the electrochemical process has found widespread utilization in industry, the use of marking stencils has limited its applicability. In an application where individual parts are to be identified by different serial numbers, the stencil must be changed between each image recording cycle. Accordingly, a large number of stencils must be kept on hand. The handling of relatively large numbers of stencils has proven to be difficult and oftentimes leads to marking errors. Mismarking of parts, particularly precision-made parts, can be costly in that the parts must be scrapped or extensively reworked.